How can I help my adc from feeding

so many games the enemy ADC is fed to shit leaving lane with 5+ kills and I am just like well fuck here I am getting 2 shot, what can I do to help my bottom lane here is what I have tried

Teleport solely to stop a fight from happening in bottom lane, rarely do I use it to help a fight mostly to stop a fight before it even happens, however now tp is on cooldown and that same fight i stopped starts again with tp on cd and I am top and they die and goes downhill for the 200+ seconds my TP is on CD rarely do i get a bottom lane that does not feed, and I don't mean lose I mean feed, 0-3 is fine anything higher is feed to me.

Now I am not saying every game some games it's even me losing but trying not to feed majority though bottom lane is yay or nay if we win, how else can I help them, early games are not short enough to leave the lane, if I left my lane it would be free gold for top lane, so I cannot roam till top tower is down but by that time bottom lane still have both T1 towers up so I cannot roam and help them from top lane.

I really want to climb and sometimes I cannot even play the game when an enemy ADC is 8-0 coming out of lane phase.